Astronomers say they’ve identified the most distant celestial object in our solar system – a speck of light more than three times farther out than Pluto, called V774104.
The object is smaller than Pluto or Eris, which rank as the largest known worlds beyond Neptune with diameters of a little less than 1,500 miles (2,400 kilometers). V774104’s brightness suggests that it’s just 300 to 600 miles (500 to 1,000 kilometers) wide. But based on a limited number of observations by the Subaru Telescope in Hawaii, astronomers estimate its distance at more than 9.5 billion miles, or 103 times the distance between the sun and Earth.
The sun-Earth distance, known as an astronomical unit or AU, provides the best measuring stick for distant objects in the solar system. Pluto is currently 33 AU from the sun, and Eris’ distance is 96 AU. V774104 is farther out, in a twilight zone that’s between the belt of icy material called the Kuiper Belt and a halo of comets called the Oort Cloud.